de Sousa Gomes Kamila, Maitan-Alfenas Gabriela P, de Andrade Lorena G A, Falkoski Daniel Luciano, Guimarães Valéria Monteze, Alfenas Acelino C, de Rezende Sebastião Tavares
Departamento de Bioquímica e Biologia Molecular, BIOAGRO, Universidade Federal de Viçosa, Viçosa, MG, 36.570-000, Brazil.
Departamento de Fitopatologia, BIOAGRO, Universidade Federal de Viçosa, Viçosa, MG, 36.570-000, Brazil.
Appl Biochem Biotechnol. 2017 Jun;182(2):818-830. doi: 10.1007/s12010-016-2364-5. Epub 2016 Dec 24.
Xylanases from the pathogen fungus Chrysoporthe cubensis were produced under solid state fermentation (SSF) using wheat bran as carbon source. The enzymatic extracts were submitted to ion exchange (Q Sepharose) and gel filtration chromatography methods (Sephadex S-200) for purification. The xylanases were divided into three groups: P1 showed better performance at 60 °C and pH 4.0, P2 at 55 °C and pH 3.0, and P3 at 80 °C and pH 3.0. Oat spelt xylan was the best substrate hydrolyzed by P1 and P3, while beechwood xylan was better degraded by P2. Carboxymethyl cellulose (CMC) and p-nitrophenyl-β-D-xylopyranoside (p-NPβXyl) were not hydrolyzed by any of the xylanases. The K or K values, using oat spelt xylan as substrate, were 2.65 mg/mL for P1, 1.81 mg/mL for P2, and 1.18 mg/mL for P3. Xylobiose and xylotriose were the main xylooligosaccharides of oat spelt xylan degradation, indicating that the xylanases act as endo-β-1,4-xylanases. Xylanases also proved to be efficient for hydrolysis of sugarcane bagasse when used as supplement of a commercial cocktail due to the increase of the reducing sugar release.
利用麸皮作为碳源，通过固态发酵（SSF）制备了致病真菌古巴金孢菌的木聚糖酶。酶提取物经过离子交换（Q Sepharose）和凝胶过滤色谱法（Sephadex S - 200）进行纯化。木聚糖酶分为三组：P1在60°C和pH 4.0时表现更佳，P2在55°C和pH 3.0时表现更佳，P3在80°C和pH 3.0时表现更佳。燕麦麸木聚糖是P1和P3水解效果最佳的底物，而P2对山毛榉木聚糖的降解效果更好。羧甲基纤维素（CMC）和对硝基苯基-β-D-木糖苷（p-NPβXyl）均未被任何一种木聚糖酶水解。以燕麦麸木聚糖为底物时，P1的Km或Kcat值为2.65mg/mL，P2为1.81mg/mL，P3为1.18mg/mL。木二糖和木三糖是燕麦麸木聚糖降解产生的主要低聚木糖，表明这些木聚糖酶起内切-β-1,4-木聚糖酶的作用。当用作商业酶混合物的补充剂时，木聚糖酶在水解甘蔗渣方面也被证明是有效的，因为还原糖的释放量有所增加。
